I'm kind of confused regarding this probability problem.
If you have 6 math books and 2 physics books. If we pick 2 books, what's the probability that the first book is a physics book
I tried solving it in 2 ways, not sure which one is correct.
1- Number of ways = 2(ways for choosing physics book) * 6 (ways for choosing math book)= 2*6 = 12
2- Naming physics books as P1, P2, finding the number of ways of each book being the first: =( 1(for P1) * 7(math books + P2)) + (1 (for P2) * 7 (math books + P1)) = 2 * 7 = 14
Which one is correct for the context of the question? Does the context means that first is physics and rest are math, or first is physics and rest are math + the remaining physics book?
Best Answer
Both considerations are wrong. You have 8 ways to choose a book. It is exactly one of the 8 described books. Provided that you correctly have given the context of question.